Which arterial blood gas result indicates the necessity for endotracheal intubation in a patient?

In critically assessing arterial blood gas (ABG) results, important parameters to look for when determining the need for endotracheal intubation include pH, PaCO2, and PaO2 levels.

The correct answer indicates a severe acid-base disturbance, specifically a significant respiratory acidosis combined with hypoxemia. The pH of 7.29 suggests that the patient is in acidosis, as normal pH values range from approximately 7.35 to 7.45. A PaCO2 level of 75 torr is considerably elevated, indicating significant hypoventilation and impaired respiratory function, which can lead to respiratory failure. Additionally, the PaO2 of 50 torr represents severe hypoxemia, as normal values are typically above 80-100 torr.

This combination of a low pH, high PaCO2, and low PaO2 reflects a critical state in which the patient's ability to maintain adequate gas exchange is compromised. When such values are present, it is a strong indication that the patient may need mechanical ventilation support due to the inability to maintain adequate respiratory function and oxygenation.

In contrast, the other choices present various combinations of ABG results that do not indicate the immediate need for intub